This invention relates to improvements in a laser machining apparatus for machining a workpiece with a laser beam.
A conventional laser machining apparatus has comprised an optical resonator including a pair of opposite spherical mirrors and a laser medium disposed between the opposite spherical mirrors to generate a laser machining apparatus beam, a beam duct operatively coupled to one of the spherical mirrors to conduct the laser beam toward a workpiece and a focussing lens for focussing the laser beam on the surface of the workpiece. The focussed laser beam irradiates perpendicularly the surface of the workpiece to cut the latter in a predetermined pattern by moving the workpiece in a pair of orthogonal directions perpendicular to the optical axis of the focussing lens so that the focussed spot of the laser beam depicts the predetermined pattern on the surface of the workpiece.
In conventional laser machining apparatus such as described above, the laser beam is randomly polarized and therefore adversely affects the working capability. This has resulted in the disadvantages that as a machining speed decreases, the workpieces has a rough machined surface due to the rotation of a plane of polarization thereof and a large cut swarf.
Accordingly, it is an object of the present invention to provide a new and improved laser machining apparatus having an improved working capability.
It is another object of the present invention to provide a new and improved laser machining apparatus having a machining speed increased so as to be at least twice that previously obtained.
It is still another object of the present invention to provide a new and improved laser machining apparatus for rendering a cut surface of a workpiece smooth with a small swarf.